Discovery of an Extremely Potent Thiazine-Based β-Secretase Inhibitor with Reduced Cardiovascular and Liver Toxicity at a Low Projected Human Dose

J Med Chem. 2019 Oct 24;62(20):9331-9337. doi: 10.1021/acs.jmedchem.9b01140. Epub 2019 Oct 8.

Abstract

Genetic evidence points to deposition of amyloid-β (Aβ) as a causal factor for Alzheimer's disease. Aβ generation is initiated when β-secretase (BACE1) cleaves the amyloid precursor protein. Starting with an oxazine lead 1, we describe the discovery of a thiazine-based BACE1 inhibitor 5 with robust Aβ reduction in vivo at low concentrations, leading to a low projected human dose of 14 mg/day where 5 achieved sustained Aβ reduction of 80% at trough level.

MeSH terms

  • Alzheimer Disease / metabolism
  • Alzheimer Disease / pathology
  • Amyloid Precursor Protein Secretases / antagonists & inhibitors*
  • Amyloid Precursor Protein Secretases / metabolism
  • Amyloid beta-Peptides / metabolism
  • Animals
  • Brain / drug effects
  • Brain / metabolism
  • Cytochrome P-450 CYP2C9 / chemistry
  • Cytochrome P-450 CYP2C9 / metabolism
  • Dogs
  • Drug Evaluation, Preclinical
  • Female
  • Half-Life
  • Haplorhini
  • Heart / drug effects
  • Humans
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Mice
  • Protease Inhibitors / chemistry*
  • Protease Inhibitors / pharmacokinetics
  • Protease Inhibitors / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Thiazines / chemistry*
  • Thiazines / metabolism
  • Thiazines / pharmacology

Substances

  • Amyloid beta-Peptides
  • Protease Inhibitors
  • Thiazines
  • Cytochrome P-450 CYP2C9
  • Amyloid Precursor Protein Secretases